Bulk wave manipulation by periodic in-filled barriers in unsaturated soil

Abstract

Band gaps or attenuation zones existing in periodic structures can filter out elastic waves propagating in both single-phase soils and saturated soils in specific frequency regions, which opens a window for designing new wave barriers to attenuate ambient vibration. However, vibration mitigation in unsaturated soil remains a significant challenge due to soil’s constitutive relation strongly relying on saturation, especially by periodic wave barriers. Based on local resonance mechanism, the performance of a periodic in-filled barrier for isolating low-frequency ambient vibration is studied. The periodic in-filled barrier is filled with a viscous material. Investigations found that the attenuation zones of the periodic wave barrier are robust to saturation and the viscosity of the in-filled material can broaden the frequency range for vibration reduction. More interestingly, periodic wave barriers in unsaturated soils can produce attenuation zones for P1 waves, which is impossible in saturated soils. Therefore, this investigation provides a promising insight for the application of periodic wave barriers to unsaturated soils.